The present invention concerns a weft carrying gripper for gripper weaving looms, more specifically a gripper carring the weft threads from the insertion side of the shed to the halfway point of the shed or further.
As is already known, the weft thread is carried over the other half of the shed by means of a drawing gripper which pulls the weft thread completely through the shed to the opposite side.
Known carrying grippers essentially comprise a gripper body that is rigidly connected to the strap or tape and includes a weft clamping device for clamping the weft threads during the transportation through the shed. Such a gripper, for example, is described in the Belgian Patent No. 902,141 owned by the assignee of this application, and the Swiss Patent No. 490544.
By using a separate clamping device, carrying grippers of the prior art have the disadvantage that they are relatively bulky, complicated and heavy, so that the maximum weaving speed is limited for technical reasons. It is indeed hardly possible to reduce the weight of such grippers because reduction of size also results in reduction of the size of the clamping device, so that clamping force control is reduced. At larger weaving speeds, however, it is necessary to have better control over and stable and fine adjustment of the clamping force.
Accordingly, any further reduction of the size of such carrying grippers in order to reduce their weight does not yield any more advantage after a given stage of reduction.
If such carrying grippers are made relatively small, these also offer the disadvantages that the fastening of the clamping device, more specifically the hingepoint of the clamping lever, becomes very weak while the hinge becomes prone to wear. Moreover, a small hinge is too weak to resist twisting that occurs in most cases when the clamping device is opened, because the pressure point for actuating the clamping lever is located eccentrically of the hinge plane.